You get this error when the file you are attempting to upload is not in a UTF-8 format. UTF-8 is the dominant character encoding for email and the web. Character encoding tells your web browser how to display special characters like ' (apostrophe) or - (hyphen).
This error occurs because the software you are using (Microsoft Excel, for example) saves the file in a different type of encoding, such as ISO-8859, instead of UTF-8. This will cause your web browser to show special characters like ' and - as ?.
How to save your file in UTF-8 format
There are a few solutions you can use to change your file to UTF-8 encoding. If your file already has ? instead of the correct characters, you will need to fix these manually before saving your file.
If you have a Gmail account or have used Google Drive previously, you can:
1. Open up Google Drive.
2. Upload your your CSV file.
3. Open your file as a Google Sheet.
4. Navigate to File>Download As>Comma-Separated Values to save the file to your computer.
5. The file should now be in UTF-8 encoding, and it will successfully upload.
If you’re using the Windows operating system and you have Notepad, you should be able to perform these steps to open your Excel file in Notepad and change the encoding:
1. Open the CSV file using Microsoft Notepad.
2. Navigate to File > Save As option.
3. From the Encoding menu, choose UTF-8 and save the file.
4. The file should now be in UTF-8 encoding, and it will successfully upload.
1. Open the CSV file with Microsoft Excel sheet.
2. Navigate to the File menu option and click Save As.
3. Click Browse to select a location to save the file.
4. Select the Save as type as CSV (Comma delimited) (*.csv) option.
5. Click Tools drop-down button and choose Web Options. A new window for web options appears.
6. On the Encoding tab, select the option Unicode (UTF-8) from Save this document as: list.
7. Click Ok, and save the file.
8. The file should now be in UTF-8 encoding, and it will successfully upload.